Studies On The Preparation Of Carbosulfan·Thiram 25% FS

Corn is one of the most important food crops in China. In the seedling stage of maize, the pests and diseases are severely restricted the production of corn, resulting in a serious decline in production and quality. The main measures to prevent and control pests and diseases of maize are using seed coating medicament before sowing. The main domestic seed coating are carbofuran, thiram, carbosulfan etc. But most of present Carbofuran?Thiram FS products are not satisfied and have many problems in such as suspensibility, formulation stability and film-forming.In this paper, on the basis of the combination of carbosulfan- thiram(6:19) formulation, the preparation of various additives in the suspension was carried out. It also studied the product quality analysis and detection method of the product, and evaluated the control efficiency through field efficacy test. The results are as follows:(1)Wetting dispersing agent, thickener, film forming agent, anti freezing agent were studied and the optimum formula of 25% carbosulfan ? thiram suspension concentrate seed coating agent was determined. The optimum formula is Thiram 19%, carbosulfan 6% dispersant 2%, 1.5% complex thickener, film former made from 0.5%, 5% ethylene glycol, coloring agents 0.5%, pH adjusting agent, concentrated hydrochloric acid 0.1%, less than the rest of the water. The performances of the preparation were measured and the results showed that the sample of Carbofuran?Thiram 25%FS we prepared had a very good quality.(2)The quality analysis and detection method of the product was determined by UV scanning and liquid phase analysis.The method is as follows: using Varian C18 column 250 mm x 4.6mm(I.D), methanol + water =94+6(V / V) as mobile phase, at a flow rate of 0.7 mL / min, and the detection wavelength was 270 nm. The linear correlation coefficients were 0.9990 and 0.9998, the relative standard deviation was 0.0349 and 0.0286, the average recovery rate was 98.80 and 99.10, respectively.(3) The field efficacy test and safety test on maize seedling were studied. The results shows that 25% Carbofuran?Thiram FS had a good control efficiency on the underground pests and stalk rot without any adverse effects on maize seedling emergence and seedling growth. The control efficiency reached more than 80% and 70%,respectively. The optimal dosage is 521~625 g /100 kg seeds.